Relative wind display and landing aid

ABSTRACT

A system for displaying information obtained along the direction of flight of an aircraft is provided. The system includes a vane assembly pivotally mounted to the aircraft having a sensor mounted thereto. The vane comprises a pointing axis configured to continuously align with the direction of the flight path of the aircraft. A display device is operatively connected to the output of the sensor for providing a display along the actual flight path of the aircraft.

FIELD OF THE INVENTION

The present disclosure relates to aircraft cockpit display systems andlanding aids, and more specifically, to systems for displaying theactual flight path of an aircraft along the direction of the relativewind vector.

BACKGROUND

Aircraft flight is dependent on the generation of lift resulting fromthe movement of an airfoil (e.g. a wing) through the air. The generationof lift is dependent upon the angle of attack of the wing, which isgenerally defined as the angle between an airfoil's chord line and therelative wind vector, or direction of flight. During various aircraftmaneuvers, including landing operations, the angle of attack of a wingmay increase in order to provide sufficient lift as airspeeds decrease.As such, the direction of a pilot's view out of, for example, thewindscreen of the aircraft, may not be representative of the aircraft'sactual flight path. In instances of significant angles of attack, it canbe difficult to judge an aircraft's actual flight path, including thetouch-down point of the aircraft during landing operations. This can beparticularly problematic for less experienced pilots, or studentslearning to fly.

It would be advantageous to have a system which displays the flight pathof an aircraft to a user, independent of the aircraft's angle of attack.

SUMMARY

According to one embodiment of the present disclosure, a sensor assemblyfor collecting data indicative of the flight path of an aircraft isprovided. The assembly includes a frame configured to attach to theaircraft. A vane is pivotally attached to the frame, with a sensormounted thereto. The vane defines a pointing axis which aligns with thedirection of the flight path of the aircraft via the force of therelative wind acting thereon. The sensor is arranged on the vane suchthat, in flight, its sensing axis is aligned in parallel with thepointing axis of the vane. In this way, the sensing axis is also alignedwith the actual flight path (relative wind) of the aircraft.

According to another embodiment of the present disclosure, a system fordisplaying information indicative of the direction of flight of anaircraft is provided. The system includes a vane assembly pivotallymounted to the aircraft. The vane assembly defines a pointing axisconfigured to align with the direction of the flight path of theaircraft. A sensor is mounted to the vane assembly. A display device isoperatively connected to the output of the sensor for providing a visualindication along the actual flight path of the aircraft.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating the angle of attack of an aircraft inflight.

FIGS. 2A-2B are diagrams illustrating the function of a wing-mountedvane according to embodiments of the present disclosure.

FIGS. 3A-3D are perspective, side, top and front views, respectively, ofa vane-mounted sensor arrangement according to an embodiment of thepresent disclosure.

FIG. 4 is a schematic diagram of an exemplary sensor and display systemaccording to an embodiment of the present disclosure.

FIG. 5 is an illustration of a system according to an embodiment of thepresent disclosure used during a landing operation.

FIGS. 6A-6C are illustrations of a display as it may appear in use withembodiments of the present disclosure.

DETAILED DESCRIPTION

It is to be understood that the figures and descriptions of the presentinvention have been simplified to illustrate elements that are relevantfor a clear understanding of the present invention, while eliminating,for purposes of clarity, many other elements found in, for example,aircraft, video and wireless communication systems. However, becausesuch elements are well known in the art, and because they do notfacilitate a better understanding of the present invention, a discussionof such elements is not provided herein. The disclosure herein isdirected to all such variations and modifications known to those skilledin the art.

In the following detailed description, reference is made to theaccompanying drawings that show, by way of illustration, specificembodiments in which the invention may be practiced. It is to beunderstood that the various embodiments of the invention, althoughdifferent, are not necessarily mutually exclusive. Furthermore, aparticular feature, structure, or characteristic described herein inconnection with one embodiment may be implemented within otherembodiments without departing from the scope of the invention. Inaddition, it is to be understood that the location or arrangement ofindividual elements within each disclosed embodiment may be modifiedwithout departing from the scope of the invention. The followingdetailed description is, therefore, not to be taken in a limiting sense,and the scope of the present invention is defined only by the appendedclaims, appropriately interpreted, along with the full range ofequivalents to which the claims are entitled. In the drawings, likenumerals refer to the same or similar functionality throughout severalviews.

Referring generally to FIG. 1, a depiction of an aircraft 10 approachinga runway 12 is provided. Aircraft 10 is progressing along an actualflight path 14 generating a relative wind vector 15 with respectthereto. The angle of attack a of aircraft 10 is defined between thiswind vector 15 (or flight path 14) and a chord line 16 defined by thewing of aircraft 10. As shown in the figure, aircraft 10 is on course totouch-down generally at point 18. It should be noted that thistouch-down point may not be visible, or easily identifiable by theaircraft's pilot, as a result of the angle of attack of the aircraft asit descends toward runway 12. Accordingly, a pilot may face difficultywhen attempting to accurately place the aircraft onto the runway.

Embodiments of the present disclosure include systems for providing avisualization of the true aircraft flight path to a pilot. In thecontext of a landing operation, for example, a pilot may be providedwith an accurate image of the touch-down point of the aircraft,independent of aircraft wing configuration, airspeed and angle ofattack. Embodiments of the present disclosure include, for example, afree or pivotally mounted vane or airfoil attached to, for example, thewing of an aircraft. A sensory device, such as a video camera, may befixedly arranged on or within the vane, such that in flight, the vaneand camera are continuously aligned with the direction of the relativewind, and thus, in the direction of the actual flight path of theaircraft. A display may be provided for presenting the pilot with avisual image along this flight path. In this way, during, for examplelanding operations, a pilot will be provided with a visualization of theapproach path and actual touch-down point of the aircraft.

FIGS. 2A and 2B provide a visual representation of the functionality ofa free or pivotally mounted vane according to embodiments of the presentdisclosure. Referring generally to FIG. 2A, a wing 11 of an aircraft inlevel flight is shown. As illustrated, flight path 14 of the aircraft isgenerally level, generating a corresponding level relative wind vector15. A vane element 13 is pivotally or otherwise moveably mounted to wing11 such that the force generated by relative wind vector 15 on vane 13aligns vane 13 in the direction of flight path 14 of the aircraft. FIG.2B illustrates the same pivotally mounted vane 13, wherein wing 11 isshown with an increased angle of attack (e.g. during a landingoperation, or other low-speed flight). Despite this change in angle ofattack, vane 13 remains aimed in the direction of relative wind 15,corresponding to flight path 14 of the aircraft.

Referring generally to FIGS. 3A-3D, systems of the present disclosuremay utilize a similar vane arrangement for accurately displaying theactual flight path of an aircraft along the direction of the relativewind vector. In the illustrated embodiment, a sensor assembly 20comprises a sensor 21 (e.g. an optical, video, infrared, or thermalcamera), including a lens 25, arranged within a generally cylindricalhousing 24. Housing 24, along with one or more airfoil elements 28, maycomprise all or part of a wind vane arrangement 22. Housing 24 ispivotally connected to a support frame 26 configured to mount vanearrangement 22 to, for example, the wing or fuselage of an aircraft(i.e. in an area of the aircraft exposed to undisturbed airflow). In theexemplary embodiments, housing 24 is attached to frame 26 via a mountingcollar 27, which comprises pivot points or axes 23 (e.g. axles orfasteners) for connecting with frame 26. Airfoil element(s) 28 aids inaligning a pointing axis of vane arrangement 22 in the direction of therelative wind during flight. More specifically, by exposing vanearrangement 22 to relatively “clean” air, its pointing axis will beurged by the relative wind into a direction parallel with the actualflight path of the aircraft.

Still referring to FIGS. 3A-3D, in the illustrated embodiment, sensor 21and housing 24 are fixedly arranged coaxially along a common axis x,ensuring that the viewing area, or sensing axis, of the camera willremain in line with the relative wind/vane direction. It should beunderstood, however, that other embodiments may include a sensory devicearranged, for example, on an external surface of an airfoil, housing orvane, without departing from the scope of the present invention. Inthese embodiments, the sensor and vane may be collimated (i.e. arrangedin parallel). In any of these described embodiments, the pivoting axis23 of the sensor may be arranged generally perpendicular with respect tosensor axis x.

In order to ensure accurate in flight operation of sensor assembly 20,it may be necessary to balance vane arrangement 22 with respect to frame26 about its pivoting axis. A balanced arrangement ensures that theangle of the pointing axis of vane arrangement 22 will be dictated onlyby the direction of the relative wind, and not by any internalimbalances. With reference to the exemplary figures, this balancing maybe achieved by slidably arranging housing 24 within mounting collar 27,such that the position of housing 24 relative to collar 27 may bealtered along axis x until the assembly is balanced about pivoting axis23. Moreover, housing 24 may be rotatably arranged within collar 27 soas to allow for aligning the camera's field of view (e.g. rotating thecamera to vertical). Once balanced and aligned, housing 24 may besecured (e.g. clamped) to collar 27. Similarly, airfoil elements 28 maybe rotatably mounted to housing 24, allowing for optimal alignment ofthese elements once mounted to the aircraft.

While a slideable collar and housing arrangement is shown, it should benoted that any suitable means to balance sensor assembly 20 to amounting apparatus may be implemented without departing from the scopeof the present invention.

It should be understood that embodiments of the disclosure may bemounted to suitable portions of the aircraft without departing from thescope of the present disclosure. In one embodiment, assembly 20 may bemounted to the underside of a wing (11, FIGS. 3B and 3D) and may extendforward into relatively undisturbed air. The housing may be configuredto “see” relative wind, usually found ahead of the aircraft body andoriented generally forward looking. Moreover, while FIGS. 3A-3Dillustrate an exemplary vane configuration, including an airfoil elementarranged on housing 24 for achieving directional stability along therelative wind vector, it should be understood that this arrangement isprovided only for exemplary purposes only, and other suitable designs orconfigurations may be implemented without departing from the scope ofthe present disclosure.

Embodiments of the sensor assemblies described above may be implementedinto a system for displaying captured data (e.g. an image) along theflight path of an aircraft. For example, FIG. 4 illustrates a flightpath display system 30 including a subsystem 31 which may beincorporated into a movable sensor assembly, such as assembly 20 shownin FIGS. 3A-3D. Subsystem 31 includes at least one sensor 33, such as avideo camera, for capturing an image along the actual flight path of anaircraft as set forth above. The output of sensor 33 may be provided to,for example, a transmitter or a transceiver, such as a radio frequency(RF) transceiver 36. RF transceiver 36 may be configured to wirelesslytransmit data output from sensor 33 to a second subsystem 32. A powersupply 37, such as a battery, may be provided for powering one or bothof the sensor(s) and the transceiver, as well as any additional systemcomponents not illustrated for the purposes of clarity. It should beunderstood that all of these components may be arranged within thehousing of the sensor assembly (e.g. housing 24 of FIGS. 3A-3D) andconnected via wired or wireless connections to associated components.

Subsystem 32 may be located, for example, in the cockpit of theaircraft, and may comprise a corresponding receiver/transmitterarrangement, such as a second RF transceiver 38 responsive to RFtransceiver 36 for receiving data (e.g. video data), or for transmittingsignals for controlling sensor 33. Received data may be supplied to, forexample, a video controller and/or a display device 39 (e.g. a monitor,“heads up” cockpit display, or projector system) for providing areal-time video display along the flight path of the aircraft.

It should be understood that additional components, such as an operatorinterface 45 for controlling various features of system 30 may also beprovided. Further, subsystem 32 may be powered by, for example, theaircraft's power supply, or a separate power supply 44. Further still,while a wireless connection between subsystems 31,32 is shown, it shouldbe understood that embodiments of the present disclosure may beimplemented with wired connections.

FIG. 5 illustrates an embodiment of the present disclosure implementedinto an aircraft cockpit. In the figure, the environment as projected bythe camera arrangement 42 is superimposed on the environment as viewedby the pilot 41. By providing an indicator or reticle 44 within thecenter of the displayed flight path image 42 projected via the camera, apilot is provided with an accurate target or indication of the truetouch-down point of the aircraft on the runway.

Referring generally to FIGS. 6A-6C, the functionality of systemsdisclosed herein as a landing aid will be further described. FIG. 6Ashows a screen or display 50 used to present the output of avane-mounted camera assembly according to embodiments described herein.As shown, an indicator 54 (e.g. a recticle corresponding to the opticalcenter of the camera or sensor) conveys to a pilot that the aircraft'stouch-down point is short of the runway (see touch-down point 17 in FIG.1). In this instance, a pilot may, for example, alter the touch-downpoint by aligning indicator 54 with a target position on runway 52, suchas that illustrated in FIG. 6C, by increasing the engine power setting,thereby increasing the groundspeed of the aircraft, to correct for this“short” landing scenario. Referring generally to FIG. 6B, the flightpath display system according to embodiments of the present disclosureindicates that the actual touch-down point of the aircraft is “long”(see touch-down point 19 in FIG. 1). In this instance, a pilot mayreduce the engine power setting, thereby decreasing the groundspeed ofthe aircraft, in order to alter the touch-down point of the aircraft to,for example, that indicated in FIG. 6C.

While embodiments described herein may be particularly useful forlanding operations, it should also be understood that embodiments of thepresent disclosure may be used in various stages of a flight. Forexample, at any angle of attack an aircraft is capable of flying at aconstant altitude with various power settings. During these conditions,the relative wind vane is always pointing at the horizon. Thus,embodiments of the present invention may also aid a user in holding aconstant heading during level flight, as well as control or maintainaltitude.

It should be understood that sensory arrangements exist for displayingan aircraft's angle of attack to a pilot via a visual indicator. Thesesensors are typically zeroed to the effective chord line of a wing orairfoil. However, these chord lines may change as, for example, leadingand trailing edge flap extensions are deployed during landingoperations. As such, many conventional angle of attack sensors do notremain accurate during various maneuvers. In contrast, the free vanearrangements of the present disclosure are not electrically zeroed toany aircraft parameter, such as wing cord line axis. Thus, theiroperation remains completely independent of, for example, flapdeployment combinations, trim, pitch, and power settings, and alwaysalign with any relative wind resulting from the actual flight path of anaircraft.

It follows that embodiments of the present disclosure may provide asignificant advantage over, for example, a system utilizing a moveablecamera which is steered (e.g. servo-controlled) according to an outputof an angle of attack sensor. As set forth above, as these angle ofattack sensors are normally zeroed to a predetermined chord line of awing, alterations in, for example wing flap configuration, will resultin a different chord line, thereby deleteriously affecting the accuracyof the angle of attack sensor. Embodiments of the present invention mayavoid this zeroing error, in addition to avoiding the need forcorrection methods for these errors, by providing a camera which iscontinuously and accurately aimed in the direction of the flight path ofthe aircraft.

While the foregoing invention has been described with reference to theabove-described embodiment, various modifications and changes can bemade without departing from the spirit of the invention. Accordingly,all such modifications and changes are considered to be within the scopeof the appended claims. Accordingly, the specification and the drawingsare to be regarded in an illustrative rather than a restrictive sense.The accompanying drawings that form a part hereof, show by way ofillustration, and not of limitation, specific embodiments in which thesubject matter may be practiced. The embodiments illustrated aredescribed in sufficient detail to enable those skilled in the art topractice the teachings disclosed herein. Other embodiments may beutilized and derived therefrom, such that structural and logicalsubstitutions and changes may be made without departing from the scopeof this disclosure. This Detailed Description, therefore, is not to betaken in a limiting sense, and the scope of various embodiments isdefined only by the appended claims, along with the full range ofequivalents to which such claims are entitled.

Such embodiments of the inventive subject matter may be referred toherein, individually and/or collectively, by the term “invention” merelyfor convenience and without intending to voluntarily limit the scope ofthis application to any single invention or inventive concept if morethan one is in fact disclosed. Thus, although specific embodiments havebeen illustrated and described herein, it should be appreciated that anyarrangement calculated to achieve the same purpose may be substitutedfor the specific embodiments shown. This disclosure is intended to coverany and all adaptations of variations of various embodiments.Combinations of the above embodiments, and other embodiments notspecifically described herein, will be apparent to those of skill in theart upon reviewing the above description.

What is claimed is:
 1. A sensor assembly for conveying flight pathinformation comprising: a frame configured to attach to an aircraft; avane pivotally attached to the frame; and a sensor mounted to the vane,wherein the vane comprises a pointing axis configured to align with thedirection of the flight path of the aircraft via the force of therelative wind acting on the vane.
 2. The assembly of claim 1, whereinthe sensor is arranged within a housing.
 3. The assembly of claim 2,wherein the housing is pivotally mounted to the frame.
 4. The assemblyof claim 2, wherein the housing comprises a generally cylindrical body,and wherein the sensor has its sensing axis arranged coaxially with thehousing.
 5. The assembly of claim 1, wherein the sensor comprises avideo camera.
 6. The assembly of claim 1, wherein the sensor assemblyfurther comprises a transmitter.
 7. The assembly of claim 1, wherein thesensor has a sensing axis generally parallel to the pointing axis of thevane such that the sensing axis is aligned with the direction of therelative wind.
 8. The assembly of claim 7, wherein the sensing axis isorthogonal to the pivoting axis of the vane.
 9. The assembly of claim 1,further comprising a collar slidably mounted to the housing.
 10. Theassembly of claim 9, wherein the collar is pivotally mounted to theframe.
 11. The assembly of claim 1, wherein the sensor comprises anoptical sensor.
 12. A system for displaying the flight path of anaircraft comprising: a vane assembly pivotally mounted to the aircraft,the vane assembly comprising a pointing axis configured to align withthe direction of the flight path of the aircraft via the force of therelative wind acting on the vane assembly; a senor mounted to the vaneassembly; a display device responsive to the output of the sensor fordisplaying a visual indication of the actual flight path of theaircraft.
 13. The system of claim 12, further comprising a transmitterresponsive to the output of the sensor.
 14. The system of claim 13,further comprising a receiver operatively connected to the displaydevice and responsive to the transmitter.
 15. The system of claim 12,wherein the sensor has its sensing axis collimated with a pointing axisof the vane assembly.
 16. The system of claim 12, wherein a sensing axisof the sensor is generally orthogonal with respect to the pivoting axisof the vane assembly.
 17. The system of claim 12, wherein the sensor isarranged within a housing.
 18. The system of claim 12, furthercomprising a mounting frame for pivotally mounting the vane assembly theaircraft.
 19. The system of claim 18, wherein the vane assembly isslidably mounted with respect to the frame.
 20. The system of claim 12,wherein the display device comprises at least one of a video display anda video projector.